Welcome to Journal of Tea Science,Today is

Journal of Tea Science ›› 2015, Vol. 35 ›› Issue (3): 271-280.doi: 10.13305/j.cnki.jts.2015.03.010

Previous Articles     Next Articles

Screening and Culture Medium Optimization of Polyphenol Oxidase Producing-Fungi from Endophytes of Tea Plant (Camellia sinensis)

ZHANG Wanrong1, WU Tingyu2, YANG Minhe1,2, *   

  1. 1. College of Life Science, Fujian Normal University, Fuzhou 350108, China;
    2. Engineering Research Center of Industrial Microbiology Affiliated to Ministry of Education, Fujian Normal University, Fuzhou 350108, China
  • Received:2014-10-29 Revised:2015-02-10 Online:2015-06-15 Published:2019-08-23

Abstract: Five kinds of phenolic materials, including guaiacol, alpha-naphthol, gallic acid, L-tyrosine and tannic acid, were used as the substrates to screen polyphenol oxidase-producing fungal strains. Four out of 14 endophytic fungal strains of tea plant (Camellia sinensis) were selected by agar plate screening methods. Strain CSN-13 was obtained for its color ring size and color depth, which owned a powerful production capacity of polyphenol oxidase. A preliminary analysis for nutritional components of strain CNS-13 was conducted. The results showed that among 6 kinds of carbon sources, wheat bran was the best for its promoting effects upon polyphenol oxidase production. Ammonium nitrate showed the most significant promotion among 5 kinds of nitrogen sources. Enzyme production was significantly promoted when tea infusion was added into the fermentation medium. With the adoption of orthogonal design, the fermentation medium for enzyme production was preliminarily optimized. The optimized medium contains wheat bran (40βg·L-1), ammonium nitrate (15βg·L-1), tea (4βg·L-1), KH2PO4 (2βg·L-1), MgSO4·7H2O (0.5βg·L-1), CaCl2 (0.075βg·L-1), and CuSO4·5H2O (0.01βg·L-1). By using the optimized medium, enzyme activity could reach 241 U·mL-1·min-1 under culture conditions with 28℃ temperature for 5 days, which was 8.5 times higher than that of before optimization. Strain CSN-13 and the fermentation medium in present study offered an alternative for the further development of polyphenol oxidase.

Key words: Camellia sinensis, endophyte, polyphenol oxidase, fungal strain screening, medium optimization

CLC Number: